(郑州大学 材料工程学院, 郑州 450002)
摘 要: 研究了Al5TiB加入量对Mg-8Zn-4Al-0.3Mn铸造镁合金时效过程的影响。 结果表明, 未加Al5TiB的Mg-8Zn-4Al-0.3Mn合金的时效析出过程为: 过饱和固溶体→细小弥散析出相→再结晶软化和析出相的聚集长大; 添加Al5TiB的Mg-8Zn-4Al-0.3Mn合金的时效析出过程为: 过饱和固溶体→细小弥散析出相→析出相的聚集长大。 固溶处理后, 与未加Al5TiB的合金1#相比, 合金2#、 3#、 4#显微硬度值分别提高了2.8%、 6.8%、 9.1%;人工时效后, 与未加Al5TiB的合金1↑#相比, 合金2#、 3#、 4#显微硬度峰值分别提高了9%、 11.2%、 5.2%。 随着Ti元素在合金中含量的增加, 合金的析出相形成激活能呈先增大而后减小的变化规律。
关键字: Mg-8Zn-4Al-0.3Mn合金; Al5TiB; 固溶处理; 时效过程
(School of Materials Engineering, Zhengzhou University, Zhengzhou 450002, China)
Abstract:The effects of Al5TiB addition on aging process of Mg-8Zn-4Al-0.3Mn alloys have been studied. The results show that the aging precipitation process of Mg-8Zn-4Al-0.3Mn alloy without Al5TiB addition is: supersaturated magnesium solid solution→small and dispersed precipitation phases→recrystallization soften and aggregation growth of precipitation phases, and that of magnesium alloys with Al5TiB addition is: supersaturated magnesium solid solution→small and dispersed precipitation phases→aggregation growth of precipitation phases. After solid solution treatment, comparison with 1# alloy without Al5TiB addition, microhardness values of alloy 2#, 3# and 4# increase by 2.8%, 6.8% and 9.1%, respectively and after artificial aging, those of alloy 2#, 3# and 4# increase by 9%, 11.2% and 5.2%, respectively. Precipitation formation activation energy of alloy increases firstly and then decreases with increasing content of Ti element.
Key words: Mg-8Zn-4Al-0.3Mn alloy; Al5TiB; solid solution treatment; aging process